Axle-wheel-type host compound

Irradiation of crystalline host-guest complexes of the nitrones 23 with the axle-wheel-type host compound (R,R)-( — )-4 gave the optically active oxaziri-dines 24 (Scheme 6) [48]. In particular, the enantioselectivities for the formation of 24d and 24e were perfect. 

Irradiation of the 2 1 host-guest crystals of cyclohex-2-enone 81 with the axle-wheel-type host compound (— )-5 as an aqueous suspension caused regio- and enantioselective [2 + 2] photodimerization to afford the (— )-anti-head-to-head dimer 82 of 48% ee in 75% chemical yield (Scheme 18) [86]. Similarly, solid-state photolysis of the 3 2 complex of cycloocta-2,4-dien-l-one 83 with (R,R)-( — )-4 gave the (-)-anti-head-to-head dimer 84 in moderate optical yield [87]. 

Irradiation of crystalline host-guest complexes of the nitrones 23 with the axle-wheel-type host compound — )-4 gave the optically active oxaziri-... 

Table 1. Crystal data for structures of inclusion compounds with wheel-and-axle type hosts containing large aromatic end groups Jl)...

Draper has recently reported a study that cuts across three of the host structural systems discussed earlier, namely compounds 99a-c (axial aromatic, Section 4.1), lOOa-c (wheel and axle, Section 4.3), and lOla-c (trigonal symmetry, Section 8). The majority of these molecules exhibit inclusion properties and their crystal structures provide a revealing comparison of these host types. 

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